How much power and CO2 can waste heat recovery save in a 2 x 100 TPD DRI plant?
About 23.5 million kWh of grid power a year. TERI's 2025 Bankura profile says a 2 x 100 TPD coal-based DRI plant can run a 5 MW waste heat power plant, costing about Rs 500 million, avoiding roughly 15,900 t CO2 at the FY 2025-26 grid factor. Better kiln lining saves another 580 t of coal per kiln.
Where the heat is
Off gas leaves a DRI rotary kiln at 950 to 1,000 C. A waste heat boiler turns it into high pressure steam for a turbine; the power runs the plant and any surplus can go to the grid. The kiln shell itself runs at 180 to 250 C, and radiation from it is about 5% of the heat input.
Bankura's DRI plants
- 10 DRI plants make 1,396,500 t a year on 1.53 million t of domestic and imported coal: 700,875 toe and 2.87 million t CO2 by TERI's count.
- That is about 64% of the cluster's energy (700,875 of 1,089,563 toe). TERI's text says 48%, but its own table gives 64%.
Is 5 MW worth it
Rs 500 million for 23.5 million kWh a year is about Rs 21 of investment per kWh saved each year. Divide that by what you pay per kWh to get a rough payback before running costs. At an assumed Rs 7 per kWh it is about three years; use your own tariff and steam data.
What it does to your carbon numbers
- Kiln coal does not change, so direct emissions stay where they are.
- Grid purchases fall, so your Scope 2 figure and the footprint a domestic buyer sees fall with them.
- Do not put a grid factor on the waste heat power; its fuel is already counted in the kiln.
- Sponge iron counts direct emissions only under CBAM, so waste heat power does not lower the CBAM figure. Coal burnt per tonne of sponge iron does.
Two kiln changes in the same profile
- Mullite-based low conductivity lining on a 100 TPD kiln: about 580 t of coal a year.
- Pellets instead of 5 to 20 mm ore lumps: better yield, fewer fines, less coal per tonne.
Savings at FY 2025-26 factors (estimate)
- Waste heat power: 23.5 million kWh x 0.675 kg = about 15,860 t CO2 a year
- TERI's profile gives 16,685 t, using a slightly higher grid factor
- Better lining: 580 t Indian coal x 1.76 = 1,021 t CO2; imported coal at 2.44 = 1,415 t
- Payback: Rs 500 million / (23.5 million kWh x Rs 7) = about 3 years, before running costs
Plant figures from TERI's 2025 Bankura energy profile. The Rs 7 per kWh tariff is an assumption for the example. Grid factor from CEA for FY 2025-26.
What Senseible does here
The green loan check shows what a lender asks before funding a waste heat plant. Senseible reads coal invoices and power bills into monthly records, so the grid power saved shows against your own baseline.
- Green loan check
- Bankura cluster: energy and CO2
- Counting waste heat power
- Durgapur DRI belt carbon
- Is sponge iron covered by CBAM?
Sources: TERI, Energy profile: Bankura secondary steel cluster (2025), CEA, CO2 Baseline Database for the Indian Power Sector, version 22.0, IPCC 2006 Guidelines, Volume 2 Energy, CBAM Regulation (EU) 2023/956, consolidated text
Last reviewed 2026-10-31.